1. Field of the Invention
This invention relates to a hub retainment device and, more particularly, to a device to secure the hub on the coupling shaft and to prevent the hub being pulled off the shaft when the roll spade is removed from the coupling sleeve.
2. Brief Description of the Prior Art
Gear-type spindle couplings for connecting the spade ends of the rolls of a rolling mill to a prime mover or gear are old and well known in the art. In the usual type of spindle coupling, the sleeve at an end connects to the prime mover and the sleeve at the other end to the spade end of the roll. Each sleeve is drivingly connected by means of gear teeth to hubs which are fixed on opposite ends of the spindle shaft by means of splines or the like. When it becomes necessary to repair or replace the rolls of the rolling mill, the roll ends are withdrawn from the sleeve. Because of the close tolerances necessary to transmit torque between the sleeve and roll end, withdrawal of the roll ends often causes the sleeve to move with the roll as it is being withdrawn. Movement of the sleeve causes it to butt the hub urging it to move off of the coupling shaft. To prevent the hub from sliding, prior art couplings have used a retaining ring which is bolted to the shaft. While such an arrangement ordinarily will prevent movement of the hub, it has been found on occasion that the bolts will shear allowing them to fall into an area where the gear teeth of the sleeve and hub mesh. If the bolts enter this area, severe wear and damage to the teeth takes place and the entire coupling must be disassembled to remove the bolt heads. This increases the time the mill is shut down and adds to the cost of maintenance.